Cutting trolley with a front and a rear attachment device

ABSTRACT

A cutting trolley ( 2 ) includes a frame structure ( 12 ) and at least two rear wheels ( 30, 31 ) on a rear shaft ( 32 ) and at least one front wheel ( 20 ), for a cutter ( 31 ) of the type including a circular cutting blade ( 5 ) in a front end of the cutter, and a front handle ( 6 ) and a rear handle ( 7 ). The trolley also includes a cutter carrier ( 13 ), said cutter carrier including a front attachment device ( 36 ) and a rear attachment device ( 37 ) for the attachment of the cutter on the carrier via said front handle and said rear handle, respectively, for trolley carried operation of the cutter.

TECHNICAL FIELD

The present invention relates to a cutting trolley with a framestructure and at least two rear wheels on a rear shaft and at least onefront wheel, for a cutter of the type including a circular cutting bladein a front end of the cutter, a front handle and a rear handle.

BACKGROUND OF THE INVENTION

Cutters of the above mentioned type are normally hand-operated. Sawingin asphalt and concrete floors with such hand-operated cutters, whichalso are referred to as power cutters or cutting machines, however is adifficult task not the least from an ergonomical point of view.Therefore, trolleys have been designed and are conventionally used forcarrying the cutter during the performance of that type of work. Thecombination of a cutting machine which basically is intended for manualoperation of the cutter, and a trolley for such machine, however, givesrise to new problems. One such problem is due to the fact that the frontand rear handles of cutting machines designed for manual operationconventionally are connected to the machine body via anti-vibrationmeans. Therefore, alignment problems can arise when using the trolleyand the cutter in combination, such that the direction of the grooveestablished by the cutting blade will deviate from the direction ofmovement of the trolley. Further, there is a long felt want to provide acutting trolley which allows the provision of a more easily controlledsawing depth than has been possible with cutting trolleys used today.

BRIEF DISCLOSURE OF THE INVENTION

It is the purpose of the present invention to provide an improvedcutting trolley of the type mentioned in the preamble. More particularlyit is a purpose to address one or all of the problems mentioned aboveand/or in the following. This task may be satisfied if the cuttingtrolley is designed according to the appending claims. Furthercharacteristic features and aspects of the invention will be apparentfrom the following detailed description of a preferred embodiment of thecutting trolley of the invention.

BRIEF DESCRIPTION OF DRAWINGS

In the following description of a preferred embodiment, reference willbe made to the accompanying drawings, in which

FIG. 1 is a perspective view of an assembly, including the cuttingtrolley with a mounted cutter and a water tank, showing the front andleft hand side of the assembly,

FIG. 2 shows the cutting trolley and the cutter from the left, thecutter sawing in a floor or the like,

FIG. 3 shows the cutting trolley and the cutter ready fortransportation,

FIG. 4 is a schematical front view of the trolley,

FIG. 5 is a perspective view showing the right hand side of the trolleyand a cutter mounted on the trolley,

FIG. 6 is an enlarged, perspective view showing a device for controllingthe sawing depth,

FIG. 7 shows a front attachment device for the attachment of the cutter,

FIG. 8 shows a rear attachment device for the attachment of the cutter,

FIG. 9 shows a device for lateral displacement of the rear attachmentmember for alignment control and/or curve cutting adjustment of thecutting blade, the rear handle of the cutter being clamped in said rearattachment device, and

FIG. 10 schematically illustrates a linkage system including the saidcontrol device.

DESCRIPTION OF A PREFERRED EMBODIMENT

With reference first to FIGS. 1 and 2, a complete assembly consisting ofa cutting trolley 2, a cutter 3 and a water tank 4 is generallydesignated 1. The cutter 3 is a petrol-powered cutter of a type knownper se, which per se does not form part of the invention. It includes arotational, diamond-equipped cutting blade 5 in its front end. In FIG. 1and FIG. 2 it is mounted on the cutting trolley 2 for easy cutting inasphalt, a concrete floor, or the like. Normally, however, it ishand-held and manually operated and is for that purpose provided with afront handle 6 and a rear handle 7. Both handles are attached to themachine body 8 of the cutter 3 via anti-vibration devices, which providea considerable flexibility of the handles relative to the machine bodyand hence also to the cutting blade 5 and vice versa.

The cutting trolley 2 has two main units, namely a first unit referredin this text as frame structure 12, and a second unit referred to ascutter carrier 13. Other features of the trolley includes a handle 14for pulling the trolley 2 forwards or rearwards, and a control device,general designated 15 for control and adjustment of the sawing depth.

The said first main unit referred to as frame structure 12 includes afirst link 18 and a second link 19. A single front wheel 20 is mountedin a front end of the first link 18. The first link 18 is elongated andhorizontal or forms a small angle to the horizontal plane depending onthe sawing depth. In view of the comparatively small angle ofinclination, which can be adjusted as will be described in thefollowing, the first link can be referred to as generally horizontal.From the same reason the second link 19 can be described as generallyvertical, although it can be inclined as well in a controlled mannerwith reference to a vertical plane as also will be explained in thefollowing. A lower end of the second link 19 is pivotally connected to arear end of the first link 18. A top end of the second link 19 isconnected via a pivot 21 to said device 15 for control of the sawingdepth.

The said second main unit referred to as cutter carrier 13 basicallyconsists of a dog-leg shaped tube structure including a front, lowersection 25, and a rear upper section 26. An end portion of said lowersection 25 of the cutter carrier 13 is rotationally connected to saidfirst link 18 of the frame structure 12 in a position of said first linkbetween the front wheel 20 and the rear end of the first link 18. Theend of said rear, upper section 26 of the cutter carrier 13 is connectedto an upper horizontal shaft 27, which has the shape of a sleeve ofshort length, FIG. 4. The cutter carrier 13 is provided with a bearinghousing 28 in the region of the bend of the dog-leg shaped tubestructure constituting said cutter carrier 13. The trolley 2 has tworear wheels 30, 31 preferably arranged in the respective ends of ahorizontal wheel shaft 32 which is journalled in said bearing housing28. The centre of rotation 34 of the rear wheels 30, 31 defines a centreof turning the cutter carrier 13. If the cutter blade 5 shall belowered, the cutter carrier is tilted forwards about said axis ofrotation 34 of the rear wheels, and is vice versa raised to a moreupraised position if the cutting blade shall be raised to a higherlever, as will be explained in the following.

The wheel shaft 32 can be fixed in chosen positions relative to thecutter carrier 13 by means of a locking screw 33. The locking screw canbe undone, allowing the wheel shaft 32 and the wheels 30, 31 to belaterally displaced relative to the cutter carrier 13 and locked in anynew position.

A front attachment device 36 and a rear attachment device 37 areprovided for the attachment of the cutter 3 on the cutter carrier 13 viathe front handle 6 and the rear handle 7 of the cutter 3, respectively.The front attachment device 36 is shown in its non-locking position at alarge scale in FIG. 7. The front attachment device 36 is mounted on thefront lower section 25 of the cutter carrier behind a splash apron 23 atthe front end of said section 25 in front of the position of a frontpivot 38 which is a member for rotational connection of the front lowersection 25 of the cutter carrier 13 to said first link 18 of the framestructure 12. The attachment device 36 consists of a bracket 39, whichis fixedly secured to the front end of said front section 25 of thecutter carrier, and a turnable locking member, in this text referred toas latch 40. The bracket 39 has a concave, curved bottom portion 41fitting the shape of a lower section of a front, curved section of thefront handle 6 of the cutter 3. When the front handle 6 has beenpositioned on the bracket 39, the latch 40, FIG. 7, is turned to lockingposition over the front handle 6 resting on the curved bottom portion 41of the bracket 39. When the curved bottom portion of the front handle 6is secured between the bracket 39 and the latch 40, the curved design ofthe bottom portion 41 of the attachment device allows the curved sectionof the front handle 6 of the cutter 3 to be slightly turned in the frontattachment device 36, which also allows the entire cutter 3 to beslightly turned, as will be explained in the following, for alignmentcontrol and/or curve cutting adjustment of the cutting blade 5. Analternative to this control would be to make the wheel shaft 32steerable.

The rear attachment device 37 consists of two halves, namely a first orright hand half 44 and a second or left hand half 45. The halves 44, 45,FIG. 9, are secured to a rod-shaped slide 46 via holding members 47 and48, respectively. The slide can move sideways, i.e. perpendicularly tothe longitudinal direction of the cutter 3 and of the cutting blade 5 ina sleeve 49, which is mounted sideways on the rear, upper section 26 ofthe cutter carrier 13 in a position at a distance from the upper end ofsaid upper section 26. The lateral displacements of the slide 46 isprovided by means of a knob 50 on an adjusting screw 51.

The first half 44 of the rear attachment device 37, which is secured byholder 47 to the slide 46, has a cavity 53 and the second half 45 has acavity 54, FIG. 8. In combination, when the two halves 44 and 45 areclamped together, the cavities 53 and 54 define a space which is adaptedto accommodate the rear part of the rear handle 7 of the cutter 3, FIG.5, including a throttle trigger lockout (not shown) on the upper side ofthe rear handle 7, which throttle trigger lockout is permanently presseddown when the handle 7 is accommodated in the rear handle 7, clampedbetween the two halves 44 and 45. The two halves in their holdingpositions are clamped together by means of a locking screw 55, whichextends through said second half 45, and a nut 56 on the holding member47. The locking screw 55 can be tightened and undone by means of ahandle 58. When the second half 45 is loosened, it can be folded aside,as is shown in FIG. 8. For that purpose said second half 45 and itsholder 48 are connected to the slide 46 via a hinge 52.

By means of the adjusting screw 51, it is possible to displace the rearhandle 7 in the lateral directions, when the handle is accommodated andclamped in the rear attachment device 37. When such lateral displacementis performed, the front handle 6 of the cutter 3, which is accommodatedin the front attachment device 36, is slightly turned in said frontattachment device, which is possible because of the curved design of thebottom portion 41 of the bracket 39. In the introductory part of thispatent specification, it is mentioned that the front and rear handles ofthe cutter are connected to the machine body via anti vibration memberswhich provide some flexibility to the connections, and that this maycause problems as far as the alignment of the cutting blade 5 isconcerned. This is due to the fact that the direction of the groovewhich is cut by the cutting blade may be caused to deviate from thedirection of movement of the cutting trolley 2. This is a well knownproblem in connection with cutting trolleys, which conventionally meansthat the cutting operation has to be interrupted, the position of theentire trolley be adjusted to a new position, and the cutting operationbe restarted. When cutting with a machine of the present invention,however, this problem is readily and efficiently attended to by means ofthe adjustment screw 51 which can adjust the position of the cuttercarrier and hence the cutter 3 and the cutting blade 5 for alignmentcontrol. The same adjusting members also can be employed for curvecutting adjustment.

The control device 15 for adjusting the sawing depth now will beexplained with reference also to FIG. 6. The control device includes ahandspike, generally designated 60, which is located at a high level inthe assembly 1, adjacent to the handle 14 for operating the trolley 2,on the left hand side of the assembly, which makes it easily accessibleto the operator, making it possible to adjust the sawing depth duringoperation, even if the operator is moving the trolley forwards. On thesame handle also a throttle grip 78 is provided, on the right hand sideof the trolley. By means of the throttle grip 78 the operator cancontrol the throttle via throttle wire 79. Further a device foradjusting the position/inclination of the handle 14 is provided, easilyaccessibly for the operator. This handle adjustment device includes ahandle 80 on the left hand side of the control device 15 for turning ascrew extending through the sleeve/shaft 27, which extends through thecontrol device 15. Said screw is provided for engaging or disengaging aconventional clutch 77, which connects a lower part 14 a of a tubemember, the upper part of which constitutes the handle 14, to saidsleeve/shaft 27 and hence to the trolley 2. All devices for controllingand/or for adjusting the cutting trolley and the cutter thus areprovided easily accessible for the operator which is highly advantageousnot the least from an ergonomic point of view.

The handspike 60 consists of a plate structure, which is designed andbent so as to provide an U-shaped bar 61 and two parallel panels 62 a,62 b having the contour of a quarter of a circle. The bar 61, which hasa U-shaped cross section, and the side panels 62 form integrated partsof the handspike 60. The bar 61 also includes a first cover 63 on thefront side of the bar, so that the bar 61 is completed to form a tube. Asecond cover 64 is provided between the side panels 62 in the region ofthe circular periphery of the panels.

The pivot 21, mentioned in the foregoing includes a shaft extendingthrough the side panels 62 of the handspike 60. Also the sleeve 27extends through the handspike 60, which can be turned about said sleeve27 by means of the bar 61. The centre of the sleeve 27 in other wordsforms a centre of rotation 71 of the handspike 60 as well as of thescrew (not shown) for operating the clutch 77.

A section of a toothed ring 66 has a centre coinciding with the centreof rotation of the handspike 60 about the sleeve 27. An end of thetoothed ring 66 is attached to the upper section 26 of the cuttercarrier 13 via two studs 67 at a distance from the sleeve 27 and extendsinto the space between the panels 62, inside said second cover 64. Insaid space there is also provided a device for latching the handspike 60in desired positions relative to the toothed ring 66, said latchingdevice including a latch which can be engaged between any chosen teethof the toothed ring 66 and also be released, allowing the handspike 60to be turned to a new position. The said latching device is operated bya handle 68 in the end of the bar 61, releasing the latch via a leaverwhich can be turned about a hinge 69, so that the handspike 60 can beturned to a new position, where the handspike is locked, in the newposition, a return spring causing the handle 68 to return to itsoriginal position in the bar 61.

The position of the handspike 60 relative to the toothed ring 66 isindicated through one or a plurality of openings 70 in the left hand oneof the panels 62. The position of the handspike, which corresponds to acertain sawing depth, as will be explained in the following, thus can bereadily observed and controlled.

The described frame structure 12 and cutter carrier 13 in combinationdefine a linkage system, illustrated in FIG. 10, which functions in thefollowing way for achieving a desired sawing depth or for raising thecutting blade 5 to a position above the ground level. When the cuttingblade 5 is positioned completely above the ground level, the operatingbar 61 is in an upraised position, FIG. 1. If the cutting blade 5 shallbe lowered for cutting at a certain depth, the operator moves the bar 61and hence the entire handspike 60, including also the side panels 62 a,62 b, forwards. This causes the two side panels 62 a, 62 b to turn aboutthe centre of rotation 71 of the handspike, which defines a first leaverincluded in the linkage system. The turning of the handspike 60 causesthe shaft included in the pivot 21 to be turned downwards. The movementis transferred via the pivot 21 to said second link 19 included in theframe structure 12, causing the link 19 to be moved downwards. Said link19 has the function of a push/pull-bar included in the linkage system.The pushing movement of the link 19 is transferred to said first link 18of the frame structure via a pivot hinge 74 connecting the lower end ofthe push/pull-link 19 with the rear end of the first link 18, causingthe rear end of said first link 18 to be lowered, turning the lever 18slightly about the centre of rotation of the front wheel 20. The saiddownwards directed movement of the first link 18 is transferred to thefront end portion of the front lower section 25 of the cutter carrier13, via the front pivot 38, causing said front lower section 25 of thecutter carrier to be lowered. This in turn causes the entire cuttercarrier 13 to be tilted, turning about the centre of rotation 34 of therear wheels 30, 31 until the desired working depth of the cutting blade5 is achieved, which can be observed and indicated by a correspondingdigit or other symbol on the toothed ring section 66, which can beviewed in the opening 70. When the desired depth thus is achieved, FIG.2, the handle 68 is released and returns by means of a return spring toits original position causing said latching device to lock the handspike60 in the adopted position relative to the toothed ring section 66. Whenthe cutting blade 5 shall be raised to a higher position, the controldevice 15 and the described linkage system is operated the other wayaround.

The cutter 3 is operated by the operator via a throttle grip 76 on thehandle 14 in a mode which in principle is conventional and whichtherefore will not be described in any detail. The handle 14 is, asmentioned, connected to the sleeve/shaft 27 via a lower portion of thecube structure defining the handle 14 and the clutch 77. The clutch canbe disengaged by means of the handle 80 and said screw extending throughthe sleeve/shaft 27, allowing the handle 14 to be turned forwards orrearwards, including turning forwards to a position shown In FIG. 3 forcompacting the assembly. Before moving the handle to this foremostposition, the water tank 4, resting on a shelf 82 on a lower part of thetube structure including the handle 14, for supplying cooling liquid tothe saw blade via a water hose 78 is first removed.

1-12. (canceled)
 13. A cutting trolley with a frame structurecomprising: at least two rear wheels on at least one rear shaft; atleast one front wheel; a cutter carrier, said cutter carrier including afront attachment device and a rear attachment device for the attachmentof a cutter on the carrier via a front handle and a rear handle of thecutter; a displacement device comprising an adjustment screw foradjusting the position of the cutter carrier and the cutter and cuttingblade for alignment control, whereby adjustment is possible withoutinterrupting the cutting operation.
 14. The cutting trolley of claim 13,wherein said front attachment device provides for a slight turn of thecutter.
 15. The cutting trolley of claim 14, wherein said frontattachment device has a bottom portion that provides for a slightturning of the cutter.
 16. The cutting trolley of claim 14, wherein saidfront attachment device includes a curved concavity for accommodating acorrespondingly curved section of the front handle of the cutter,wherein said front handle is capable of being turned in said frontattachment device due to lateral displacement of the rear attachmentdevice in which the rear handle is secured.
 17. The cutting trolley ofclaim 13, wherein said displacement device provides for a lateraldisplacement of the rear attachment device.
 18. A cutting trolley with aframe structure comprising: at least two rear wheels on at least onerear shaft; at least one front wheel; a cutter carrier, said cuttercarrier including a front attachment device and a rear attachment devicefor the attachment of a cutter on the carrier via a front handle and arear handle of the cutter; said frame structure including a first lower,elongated link, wherein said at least one front wheel being mounted in afront end of said first link; a second rear link which is rotationallyconnected to a rear end of said first link, said second link extendingfrom said lower end up to a control device for adjusting the sawingdepth of the cutting blade, wherein said control device being positionedat a higher level than the cutter carrier.
 19. The cutting trolley ofclaim 18, wherein said control device is provided with a handle locatedadjacent to a handle for moving the trolley.
 20. The cutting trolley ofclaim 18, further comprising a linkage system wherein said controldevice defines a first lever of the linkage system; said first lower,elongated link includes a second lever of the linkage system; saidsecond link defines a push-pull rod connecting a pivot of the firstlever to the rear end of the second lever; said cutter carrier defines athird lever, said third lever having a lower front section and a rearupper section; said lower front section is rotationally connected tosaid second lever via a pivot located between said front wheel and saidrear end of said second lever, and the upper end of said upper sectionof said third lever is connected to a sleeve/shaft, the center of whichdefines the axis of rotation of said first lever defined by the controldevice.
 21. The cutting trolley of claim 20, wherein the axis ofrotation of the rear wheels define the turning axis of the cuttingcarrier, which defines said third lever.
 22. The cutting trolley ofclaim 18, wherein a bearing housing for journaling a wheel shaft of therear wheels is provided on the cutter carrier in the region of a bend ofsaid third lever, defined by the cutter carrier.
 23. The cutting trolleyof claim 18, wherein said first link of the frame structure isapproximately horizontal, said second link of the frame structure isapproximately horizontal, and the front lower section and the rear uppersection of the cutter carrier are approximately parallel with said firstlink and said second link, respectively in at least one position of thecutter carrier.
 24. The cutting trolley of claim 23, wherein the atleast one position is an upraised position.
 25. The cutting trolley ofclaim 18, wherein said first link of the frame structure forms a smallangle with the horizontal, said second link of the frame structure formsa small angle with the vertical, and the front lower section and therear upper section of the cutter carrier are approximately parallel withsaid first link and said second link, respectively in at least oneposition of the cutter carrier.
 26. The cutting trolley of claim 25,wherein the at least one position is an upraised position.
 27. Thecutting trolley of claim 18, wherein the wheel shaft is steerable.